How To Format An SD Card On Mac [All You Need To Know]

Using an SD card on your device is an easy and affordable method of expanding its memory. Current cards keep multiple file types, so you can rest assured they will always be stored safely.

However, to use a card on a Mac, you most likely must format it first, especially if the SD card is from a Windows user. Fortunately, this article presents solutions on how to format an SD card on Mac for experienced and new users. 

How to Format an SD card on Mac?

If you’re ready to repurpose an old SD card or format new external storage and have a Mac, you should first get your SD card reader ready. If your Mac doesn’t have an integrated card reader, you can purchase an affordable external one in-store or online. 

After hooking up the card reader, you should know which file system to use. If your SD card is smaller than 32 GB, use FAT32. If it’s larger, use an exFAT system to manage SD card formatting on Mac.

Determine which system you should use to manage your external storage for Mac. To do this, download a third-party app, like Disk Utility.

After inserting the card into your reader, open the app, identify your card, and check the storage size to determine which file system to use. If using an unformatted card, you may find it labeled as NO NAME or UNTITLED.

Select Disk Utility’s erase option, which will clear the SD card on your Mac. You should back up all folders and files saved to the card if previously used. When you click Erase, you’ll also get warned that everything will be deleted, so it’s a good moment to run a check for any forgotten files.

Assign a name to your card, select the file system, and click Erase. Once you delete everything, you receive a message that the process is complete. You have now successfully reformatted the SD card on your Mac.

Depending on the card’s capacity and versatility, you can now use it on various devices. SD cards are a quick fix to expand your device's memory, as they don’t require software to function – you can just plug them in.

There are many additional ways to format the memory card on a Mac. Let’s check out a few.

Formatting an SD Card to FAT32 on a Mac 

With a 32 GB or less SD card, you should use the FAT32 system together with Disk Utility to format it. These are the steps:

• Connect SD card to Mac via card reader
• Launch the Disk Utility app
• Select your card from the list of drives
• Enter the new card name
• Select FAT32 to format
• Click Erase to start formatting the SD card on your Mac
• Wait until the process is finished and eject the card

If your SD card has more than 32 GB of memory, you should use the exFAT system for reformatting. However, FAT32 has better compatibility but doesn’t support storing or transmitting individual files over 4 GB.

SD Cards on Mac Using the Terminal

Another way to reformat an SD card on a Mac is to use the Terminal app. However, this is a more complex way of dealing with SD cards and is most suitable for advanced users. Using the Terminal app requires you to know specific commands. You may format cards of all sizes with this program. Plus, you can erase SD cards with Terminal, which Disk Utility can’t do.

These are the steps for using the Terminal app:

• Insert an SD card in the reader.
• Use Launchpad to open the Terminal app, or press Cmd+Space and type terminal.
• Type diskutil list to find your SD card.
• Look for the external and match the storage capacity.
• Type sudo diskutil eraseDisk FAT32 SDCARD MBRFormat /dev/disk4 for cards of 32 GB or smaller.
• Type sudo diskutil eraseDisk ExFAT SDCARD MBRFormat /dev/disk4 for cards larger than 32 GB.
• If necessary, enter your password.
• Wait for the command to finish.

If you are wondering how to wipe an SD card on a Mac, you can do so by using the Terminal app’s dd command. Make sure you back up your files and folders first, as this command will cause complete data loss. Follow these steps:

• Open the Terminal app
• Type diskutil list
• Find the drive you want to delete
• Ensure the drive is no longer active by typing the sudo diskutil unmountDisk /dev/diskX command
• Type sudo dd if=/dev/zero of=/dev/diskX bs=1m command to wipe an SD card on your Mac
• Wait for the app to finish
• Exit the app
• If wanting to use the card again, go back to Disk Utility to format it.

Using SD Card Formatter

You can also use the SD Card Formatter for Mac devices to clear your drive. SD Association developed this free third-party software. One of the most significant benefits of Formatter is that it won’t accidentally erase drives that aren’t SD cards.

Plus, this tool automatically reads the size of your card and determines which system to use. The steps to using Formatter are straightforward:

• Select the card
• Pick the formatting option
• Enter a new drive label
• Click Format

SD Card Formatter is available for MacOS X 10.7 Lion and above.

Possible Issues When Formatting an SD Card on Mac

If you can't erase the SD card on your Mac, there are a few things to consider. You may have caught malware, or perhaps something corrupted the card. Additionally, it is possible that the SD card is protected, or you may have improperly ejected it.

You can scan your card with an antivirus program in case of malware. Alternatively, check online for commands to remove the virus. This option tends to be more suitable for advanced Mac users. Still, using these two approaches won’t reformat your card, so you’ll keep the files.

Some SD cards are write-protected, so you won’t be able to alter the stored data. This feature keeps data protected so you can’t accidentally delete it, but it may stop you from formatting an SD card on your Mac. Here’s how you can solve this:

1. If your card came with a physical lock, toggle the switch to the opposite direction
2. Change the read-only files via Sharing & Permissions feature
3. Use Disk Utility’s First Aid tool

If your card’s formatting was with Windows, Mac isn’t able to read it. In this case, you can use an NTFS driver for Mac to access your card and reformat it.

If you improperly eject the card, you should try inserting it again and see what the program shows. It might require you to reformat it again.

Finally, try using the dd command to erase the SD card on Mac completely. However, if this fails, you should get a new card as it’s likely corrupted beyond help.

Wrap Up

An SD card is an excellent way to gain memory for your favorite photos and documents. However, you’ll need to learn how to format an SD card on Mac to use it safely.

There are a few ways to format your card, either by using a third-party or Mac’s Terminal app. If any issues arise, use the Disk Utility’s First Aid tool or the dd command to go through the process again.